CAM accounts for a substantial proportion of United States healthcare expenditures. Its integration into healthcare financing, although relatively new, is expected to increase. Washington State is one of the few states with a comprehensive legal mandate related to CAM integration. The law, initiated by the legislature in 1995, is unique - based on coverage of all provider types, rather than on a specification of precise benefits. After a series of court challenges, full implementation of the mandate was ordered for January 1, 2000. With 53 categories of licensed healthcare providers, Washington State currently licenses more CAM providers that most other states in the country. Thus, insurance claims data from Washington State provide a unique opportunity for studying one method integrating CAM into traditional mechanisms for healthcare finance. The health insurance carriers included in the study cover over 75% of the commercially insured lives in the state and sell products that vary in the richness of their benefit packages and the case mix of their enrollees. These factors will be considered in describing and building predictive models of CAM utilization and cost. Claims from 1996 will provide baseline information on CAM coverage prior to implementation of the Washington legislative mandate; claims from 2000 will provide information reflecting the first full year of post-mandate integration. The study will measure the extent to which the legislation requiring coverage of every category of health care provider has increased the integration of CAM into conventional health care financing. Analysis of insurance claims data will quantify CAM use for specific conditions for which CAM has proven efficacy and will assess the extent to which efficacy studies have been translated into real-world settings within an integrated model of financing. Analyses will describe to what extent and for what conditions integrative medicine is now funded by insurance and whether the intent of the Washington State legislation, which was to promote more cost-effective options by reducing barriers to the use of integrative medicine, has been fulfilled. The study will calculate CAM cost offsets for individual insurance carriers, both for their total enrollments and for specific populations within their enrollments. This will explore the question of whether CAM use is "complementary" (in addition to) or "alternative" (instead of) in its relationship to traditional healthcare. By looking at medical conditions for which CAM has demonstrated efficacy, the study will compare reimbursements for enrollees with and without CAM use, thus allowing an indirect measure of cost-effectiveness to be calculated. The study will assess provider behaviors of CAM and conventional practitioners through a consideration of the percentage of CAM practitioners in Washington State who participate in insurance coverage, and of the types of conventional practitioners who make CAM referrals.